Merck, 10220647001, GTP-γ-S

General description
Guanosine 5′-O-(3-thiotriphosphate), tetralithium salt (GTP-γ-S) is a non-hydrolysable analog of GTP. It is an inhibitor of phosphodiesterase in photoreceptors.
Application
GTP-γ-S has been used:
in G-Protein activation assay to assess the functionality of protease-activated receptor 4 (PAR4)
in fluorimetric guanine nucleotide exchange assay of G protein alpha subunits (Gα)
to monitor the Rac family small guanosine triphosphatase (GTPase) 2 (Rac2)-stimulated activity of phospholipase Cγ2 mutants

Biochem/physiol Actions
Guanosine 5′-O-(3-thiotriphosphate) (GTP-γ-S) activates guanine-nucleotide-binding proteins and is slowly hydrolyzed enzymatically. It inhibits guanosine triphosphatase (GTPases) more potently than guanosine triphosphate (GTP),
Preparation Note
Store powder dry at -15 to -25 °C; aqueous solutions with pH approx. 7 should be stable for six months at -15 to -25 °C.
Analysis Note
Absorption: Content is measured in aqueous solution by absorption at 254 nm.
Conditions:approx. 10 mg/ml double-dist. water
dilution: 9.8 ml double-dist. water + 0.2 ml sample.

Other Notes
For life science research only. Not for use in diagnostic procedures.